Tool for cold rolling crankshaft fillets



D. J. wULPl 2,876,528,l

Toor. FOR coLD ROLLING CRANKSHAFT FILLETs March 10, 1959 Filedl Feb. 17,195s l .ff In United States PatentY O TOOL FOR COLD ROLLING CRANKSHAFTFILLETS Donald J. Wulpi, Downers Grove, Ill., assignor to InterationalHarvester Company, a corporation of New ersey Application February 17,1956, Serial No. 566,177 1 Claim. (Cl. 29-90) ing or breaking of themetal during stresses encountered in normal operation. In the art ofmetallurgy it has also been determined that breakage can be greatlyreduced by subjecting the fillets to cold working thus in turn relievingto a great extent harmful residual stresses and in turn imparting to thefillet the more desirable metallurgical properties normally resultingfrom residual. compressive stresses at highly stressed places on thecrankshaft. It is a prime object of this invention to provide animproved tool which is readily adapted for the cold rolling ofcrankshaft fillets and the like.

Still another object is to provide an improved fillet rolling tooladapted to be quickly attached and supported by a crankshaft duringmanufacturing operation wherein the crankshaft may be rotated by anysuitable rotating machine such as a lathe or similar device.

\ A still further object is to provide an improved crankshaft lletrolling device adapted to exert a maximum pressure at any desired langleagainst the fillets which are positioned-adjacent the ends of a journalportion where the journal portion meets the. cheeks or counterweights ofthe crankshaft.

A still further object is to provide animprovedfillet rolling-toolwherein laterally displaced fillets may be placed under compressivestresses by means of rollers which are self-adjusting and self-centeringthereby providing the application of maximum pressures.

A still further object is to provide an improved selfcontained filletrolling tool for crankshafts, the tool being adapted to be supported onthe crankshaft thus eliminating the possibility of bending loads such asare encountered in the use of tools which are rigidly supported apartfrom the crankshaft per se.

A still further object is to provide a self-contained fillet rollingtool having a biasing means adapted to be preloaded to maintain a steadyand consistent compression force against the fillets which are beingrolled.

A still further object is to provide an improved fillet rolling tool forcraukshafts or the like, the said tool being readily adapted for rollingcrankshaft fillets of difierent sizes.

These and other objects will become more readily apparent from a readingof the specification in connection with the accompanying sheet ofdrawing.

In the drawing:

Figure l is a plan view of a conventional crankshaft supported on therotating elements of a conventional machine tool, such as a lathe, etc.;

Figure 2 is an enlarged side elevational view of a tool for cold rollingof crankshaft fillets showing the tool attached to a section of acrankshaft; and

Figure 3 is a plan view of a portion of a crankshaft showing a filletrolling tool in an operating position.

Referring now particularly to Figurer l, a crankshaft is generallydesignated by the reference character 10. The type of crankshaftdisclosed is conventional in internal combustion engines and comprisescentrally disposed bearing portions 11' and longitudinally spaced andoffset connecting rod journal portions 12. v Crankshafts of this typeare usually made 'by forging and integral counterweights or cheekportions 13 are joined to the journal portions 12 and include integralannular fillets 12'. The cross-sectional dimension transversely throughthe axis of each journal portion s. of course considerably less than thecross-sectional dimension of the cheek or counterweight 13. The reasonsfor the eccentric disposition of the journal portions 12 relative to thebearing portions 11 is of course obvious in the design of crankshaftsand need not be further described. The crank-- shaft` 10 furtherincludes oppositely disposed connecting portions 14 and 15. As bestindicated in Figure l, the crankshaft 1d is supported for rotation bymeans of a chuck 16 and a center or spindle 17 the latter said elementsforming part of a conventional lathe or similar machine tool.

Referring now to Figures 2 and 3, a fillet rolling tool is generallydesignated by the reference character 13.A

vtion 21 includes upper support rollers 22 journalled on a shaft 23extending through the .frame 19. Back-up rollers 24 `are disposed onopposite sides of the end por tion 21 and are suitably journalled on ashaft 25 extending through the frame 19.

A fillet compressing tool element 26 is supported on the frame 19, thesai-d element 26 including longitudinally spaced compression members 27and 28. The compression members 27 and 28 are integrally connected bymeans of a biasing member or U-shaped spring 29.

The compression member 27 has at one end a yoke 30' to which hingebrackets 31 and 32 are hingedly connected by means of a hingel pin 33.Compression rollers- 34 in turn are freely journalled on the brackets 31and 32 bymeans of shafts 33.

The compression member 28 is suitably threaded as'.

journalled in azbore 3S of the endportion 20. Oppositely'l disposedcollars 39 maintain the shaft .37 in the position indicated. A handwheel 4d is suitably connected to the shaft 37.

A pair of tension levers 4l, as best shown in Figure 3 are provided withhandle portions 42. The tension levers 41 are rigidly secured to a shaft43 extending through and journalled on the compression member 28. Eachtension lever 41 has suitably connected thereto a cable 44 the cable 44being connected to transversely spaced ears 45 provided on thecompression member 27. A stop do is provided on the end portion 20, thesaid stop being adapted to maintain the tension levers 41 in anovercenter or pretensioned positioned as indicated in the dotted linedisclosure of Figure 2. A U-shaped strap 47 is suitably supported on theframe 19, the said strap having portions thereof engaging the sides ofthe co. pression member to restrain the same against turning movement.As best shown in Figure 2 the end portion 20 of the frame 19 is adaptedto rest upon a lathe lbed 48 or similar support of the type of machinetool which is utilized.

In the operation the crankshaft is suitably supported '2,876,528vPatented Mar.. 10, 41959'- 3 Y for rotation on a lathe chuck 16 and acenter 17. The llet rolling device 19 is then positioned in the mannerindicated in Figures l and Zvwith the rollers 22 and 24 in the engagingposition indicated relative to the journal 12. The end portion 2li issuitably resting upon the lathe bed or platform 43. The tension levers41 are then moved in a clockwise direction whereupon the cables 44 areplaced under tension and draw the compression member 27 in a directiontoward the. compression member 2S whereupon the U-shaped spring 29 ispreloaded or cocked. By rotating the tension levers 41 to an overcenterposition against the stop 46 the spring 29 is suitably preloaded in thisposition. The operator then rotates the hand wheel 46 whereupon the tool26 is moved toward the journal 12. The rollers 34 freely roll on thebrackets 3l and 32 and the brackets 31 and 32 are freely hinged on theyoke 30. Thus as the tool 26 is moved toward the journal 12 the rollers34 are selfcentering and suitably engage the annular fillets 12 at thedesired angle for properly compressing the said llets. Rotation of thechuck 16 now effectuates turning of the crankshaft and the tensionlevers 41 are moved in a counterclockwise direction thereby releasingthe spring 29. The spring 29 now exerts a pressure biasing thecompression member 27 against the rollers 34 to exert the desiredpressure against the annular fillets 12. j

The compressive forces of course can be lessened or increased by simplychanging the point of attachment of the cables 44 on the arm 41. Asindicated in Figure 2, by the reference character 41 the ends of thecables are fastened by a tack weld, though variousother adjustablefastening means may be utilized. Thus the desired amount of compressiveforce can be varied depending upon the type of llets to be rolled. Thestrap 47 prevents turning movement of the tool 26 during rotation of thehand wheel 40. Longitudinal adjustment of the tool 26 relative to theframe 19 ofcourse can be achieved by various other designs. Forinstancev a square shaft 37 may be utilized in connection with the bore38 to prevent turning movement now prevented by the strap 47. In such adesign other provisions for longitudinal adjustment can readily beaccomplished.

As the crankshaft 10 is rotated, eccentric disposition of the journal ofcourse causes reciprocation of the fillet rolling device 18 in the samemanner as if a connecting rod were attached to the crankshaft. Thus asthe crankshaft journal member 12 rotates, the end portion 20 of theframe 19 which is supported on the bed 48 reciprocates with respect tothe said bed.

It is obvious of course that all of the fillets 12'of the crankshaft maybe rolled simultaneously by the utilization of a plurality of these lletrolling devices. Furthermore, changes in size in the journal portion canbe accommodated by dierent size rollers and brackets.

The free movement of the brackets 31 and 32 relative to the yoke 30permits the ready self-centering of the rolling tool. The unit iscompletely self-contained and is supported substantially on thecrankshaft itself thus eliminating the dangers of distortion or bendingwhich might be occasioned by the rigid support of a tool on any portionof a machine extraneous of the crankshaft itself. Thus distortions ofthe crankshaft are also prevented. Ready adjustment of the compressionforces is possible by the utilization of the simple tension leversindicated.

Thus it is apparent that the objects of the invention have been fullyachieved-and it must be realized that changes and modifications may bemade without departing from the spirit of the invention as disclosed orthe scope thereof as defined in the appended claim.

What is claimed is:

A device adapted for compressing laterally spaced annular metal filletsof a journal member. connected to and disposed between coaxial membershaving a sectional dimension transversely through their axes greaterthan the transverse sectional dimension of the journal mem ber,comprising; a generally U-shaped frame having iirst and second oppositeend portions, rst and second rotatable bearing membersconnected to saidfirst end por tions and adapted to engage said journal member atcircumferentially spaced portions thereof, a fillet compressing tool onsaid frame, said tool comprising first and.v

second longitudinally spaced compression members, a U-shaped springmember connecting said first and second compression members, brackets`hingedly connected to said first compression member, llet rollersrotatably.

connected to said brackets, rotatable adjustable means connected to thesecond .und portion of said frame and to said second compression" memberwhereby said tool may be reciprocated relative"` to the journal member,

spring tensioning means for pre-loading said spring including a tensionmember connected to said first compression member, and a movable lockingmember connected to said tension member and to said second compressionmember for locking said spring in a pre-loaded position, said rollersbeing movable into relative rolling engagement with the fillets, andsaid pre-loaded spring being releasable for urging said rollers intocompressive engagement with said fillets during Arotation of saidjournal member.

References Cited in the le of this patent UNITED STATES PATENTS GettyMay 6,

